I use the @Adi-lester answer and add some methods.
Method to verify if Session is Alive
public static void SessionIsAlive(HttpSessionStateBase Session)
{
if (Session.Contents.Count == 0)
{
Response.Redirect("Timeout.html");
}
else
{
InitializeControls();
}
}
Create session var in Page Load
protected void Page_Load(object sender, EventArgs e)
{
Session["user_id"] = 1;
}
Create SaveData method (but you can use it in all methods)
protected void SaveData()
{
// Verify if Session is Alive
SessionIsAlive(Session);
//Save Data Process
// bla
// bla
// bla
}